RAMI COMMUNICANTES 



969 



Nerve-fibres arising in the spinal ganglion and fibres from the ventral root pass 

 directly from the nerve-trunk into the anterior primary division of the spinal 

 nerve. This division also receives sympathetic nerve-fibres by way of the ramus 

 communicans. These latter accompany the division and are distributed to their 

 allotted elements in the territory it supphes. 



Fig. 749. — Table Giving the Approximate Areas ' of Distribution of the Different 

 Spinal Nerves with a Diagram showing Their Respective Levels of Exit from the 

 Vertebral Column. (Arranged by Dr. Gowers.) 



MOTOR 



Sterno -mastoid 

 Trapezius 



Flexors, hip 



Extensors, knee 

 Adductors 1 hip 



Abductors 



I Extensors (?) 

 Flexors, knee (?) ■ 



Muscles of leg mov- 

 ing foot 



Perineal and anal 

 muscles j 



SENSORY 



' Neck and scalp 

 Neck and shoulder 



Shoulder 



Arm 



Hand 



Front of thorax 



Xiphoid area 



Abdomen 

 (Umbilicus 10th) 



1 Buttock, upper 

 \ part 



> Groin and scrotum 



(front) 



f Lateral side 



Thigh 



front 



Medial side 

 Leg, medial side 

 Buttock, lower 



Back of thigh 



I Leg 1 



I and • except medial 



, foot J part 



Perineum and anus 



Skin from coccyx to 

 anus 



REFLEX 



Scapular 



Epigastric 



Abdominal 



[ Cremasteric 

 J 1 Elnee -joint 



Gluteal 



Foot-clonus 

 Plantar 



The rami communicantes are small, short, thread-like branches by which the 

 nerve-trunks are connected with the nearest ganglion of the vertically running 

 gangliated cord of the sympathetic (sympathetic trunk). The trunk or anterior 

 primary division of every spinal nerve has at least one of these; most of the nerves 

 have two, and sometimes there are three. The nerves of the cervical region usu- 

 ally have but one, and this is composed largely of sympathetic fibres (grey 



